PASSING OF PIERRE CHAMBON

PIERRE CHAMBON
7 February 1931 — 5 May 2026

Pierre Chambon, one of the founding figures of modern molecular biology and a pioneer of nuclear receptor research, died on the 5th of May 2026 in Strasbourg, France, at the age of ninety-five. Across a career spanning more than five decades, he transformed our understanding of how eukaryotic genes are organised, transcribed and regulated, and his work shaped entire fields ranging from chromatin biology to endocrine pharmacology.

Chambon was born on 7 February 1931 in Mulhouse, in Alsace, and remained closely tied to the region throughout his life. He studied at the Faculty of Medicine of the University of Strasbourg, where he defended his medical thesis in 1958. He was Professor emerite of the Strasbourg Medical School.  From the outset, however, his interests gravitated towards the molecular underpinnings of biology rather than clinical practice. In Strasbourg he found both an institutional home and a scientific community that would support a remarkably long arc of research.

His earliest contributions were already striking. In 1963 he was among the discoverers of poly(ADP-ribose), a then-novel polynucleotide that would later be recognised as central to DNA repair and chromatin signalling. Six years later, in 1969, his laboratory established that eukaryotic cells contain multiple distinct RNA polymerases — designated A, B and C in his nomenclature, and corresponding to the now-standard polymerases I, II and III. This finding overturned the prokaryotic paradigm of a single transcribing enzyme and laid the groundwork for the molecular dissection of gene expression in higher organisms.

Through the 1970s, Chambon's group made successive contributions that became textbook material. In 1975 they helped establish, both biochemically and by electron microscopy, that the nucleosome is the fundamental repeating unit of chromatin (Cell 4, 281–300, 1975), and they showed that histones are responsible for the supercoiling of DNA. In 1977, his laboratory was among those that demonstrated the existence of split genes — genes interrupted by introns — in animal genomes, a discovery that profoundly recast notions of how genetic information is stored and processed.

The next phase of his work focused on the regulatory architecture of eukaryotic genes. Between 1980 and 1987, his group dissected the promoter elements of protein-coding genes and contributed decisively to the identification of the enhancer — a class of regulatory sequences that act over long distances to control transcription. These studies established a conceptual framework that still underpins molecular genetics today.

It is, however, for his work on nuclear receptors that Chambon became most widely known. From 1985, his laboratory cloned the oestrogen and progesterone receptors and elucidated, step by step, how steroid hormones modulate gene expression. From 1987 onwards he extended this work to the receptors for retinoic acid and, with collaborators including the crystallographer Dino Moras, mapped their three-dimensional structure and mechanism of action. Out of these efforts emerged the recognition of an entire nuclear receptor superfamily — receptors that bind hormones, vitamins and a host of small lipophilic ligands — and a new understanding of how endocrine, developmental and metabolic signals converge on the genome. The pharmacological consequences have been far-reaching, opening therapeutic avenues in oncology, dermatology, metabolic disease and reproductive medicine. He also developed an elegant method for inducing somatic mutations in the mouse at a chosen time and in a chosen tissue, a tool that has since become indispensable to in vivo genetics.

In parallel with his discoveries, Chambon devoted himself to building institutions. He founded, in Illkirch near Strasbourg, the Institute of Genetics and Cellular and Molecular Biology (IGBMC), which became one of Europe's leading centres for biomedical research, and he directed it until 2002. With Jean-Pierre Ebel he was a co-founder of the École supérieure de biotechnologie de Strasbourg, and he later led the Institut Clinique de la Souris, a facility that pioneered conditional and tissue-specific somatic mutagenesis in the mouse. From 1993 to 2003 he held the Chair of Molecular Genetics at the Collège de France.

Recognition followed his discoveries on every continent. He received the CNRS Gold Medal in 1979, the Richard Lounsbery Prize in 1982, the King Faisal International Prize in 1988, the Robert A. Welch Award in Chemistry in 1998, the Louisa Gross Horwitz Prize twice — in 1999 and again in 2018 — the March of Dimes Prize in Developmental Biology in 2003, the Albert Lasker Award for Basic Medical Research in 2004, and the Canada Gairdner International Award in 2010, the latter recognising the elucidation of fundamental mechanisms of transcription in animal cells and the discovery of the nuclear receptor superfamily. He was elected to the French Académie des sciences and as a Foreign Associate of the United States National Academy of Sciences in 1985, and to the Royal Swedish Academy of Sciences in 1987. France honored him as Commander of the Legion of Honour and Grand Officer of the National Order of Merit.

Those who worked alongside him remember a scientist of formidable energy and exacting standards, who combined the breadth of a classical biochemist with the curiosity of an explorer. He trained generations of molecular biologists, many of whom now lead laboratories of their own, and he remained until late in life an active participant in scientific discussion, retaining an emeritus laboratory and contributing to the strategic direction of biotechnology in France.

Pierre Chambon's death closes a chapter in the history of molecular biology. Yet the questions he opened — how genes are organised, how their expression is controlled, how hormones speak to the genome — remain at the centre of contemporary biomedicine. The extraordinary body of work he leaves behind will continue to inform research and clinical practice for decades to come.

He is survived by his wife Brigitte and his 3 children.